Diverticulosis occurs when small, bulging sacs or pouches form on the inner wall of the intestine. These sacs are called diverticula. Most often, these pouches form in the large intestine (colon).

Causes

Diverticulosis is less common in people age 40 and younger. It's more common in older adults. About half of Americans over age 60 have this condition. Most people will have it by age 80.

No one knows exactly what causes these pouches to form.

For many years, it was thought that eating a low-fiber diet may play a role. Not eating enough fiber can cause constipation (hard stools). Straining to pass stools (feces) increases the pressure in the colon or intestines. This may cause the pouches to form at weak spots in the colon wall. However, whether a low fiber diet leads to this problem is not well proven.

Other possible risk factors that are also not well proven are lack of exercise and obesity.

Eating nuts, popcorn, or corn does not appear to lead to diverticular disease.